Flavors are commonly added to liquid medications to mask the unpleasant taste that many actives have. Anise flavoring has been widely used in liquid medications, in particular nighttime multi-symptom relief (MSR) cold/flu medications. Many consumers enjoy, trust, and expect this flavor.
Some consumers would like an anise flavored MSR cold/flu medication that also contains phenylephrine hydrochloride (PE), a decongestant. However, this formulation is not currently sold because it has surprisingly been found that anise flavoring comprising trans-anethole causes PE to degrade, which makes the liquid medication less effective and significantly reduces the shelf life of the product.
Therefore, there is a need for an anise flavored liquid medication that comprises PE and where the composition has a shelf life of at least 18 months.